I bought a Aquabot Pool Rover Plus last year for my 32,000 IG Vinyl Pool. My 20' x 40' pool has a steady sloped bottom from 3' to 8' deep. The rover plus will only clean the bottom but I seldom have problems with my vertical walls getting algae or dirty. I only brushed the sides twice last season. I paid 500.00 including tax, shipping, and handling. I have been very pleased with it. I like it because it runs independently from my pump/filter with very little electric power. The only issue I have with it is the cord gets tangled up with itself because it is going in a radius pattern but it only takes a few minutes to untangle it. The time it saves me vacuuming it just wonderful!!! I can throw it in after a storm and in a hour or two it is clean again.